But going into organized team activities, minicamp and summer training camp, the 49ers also have a wild card to play: Lawrence Okoye.

Okoye, the former British Olympic discus thrower and rugby player, was signed as a free agent by San Francisco last April – despite never having played football. He signed as a defensive lineman, and got work in the 49ers’ 3-4 defense in training camp. In August, he was placed on injured reserve after suffering a sprained knee in the team’s third preseason game.

The time on injured reserve meant Okoye couldn’t practice with the team, but he could attend meetings, study and watch games and practices. So, 2013 was a learning year for Okoye without the pressures of producing. He could take his time and soak in the NFL.

Recently, Taylor Price of 49ers.com put Okoye’s development on his list of 20 offseason storylines for the team, noting that: “Okoye … soaked up every bit of knowledge during his first full season with the team. Now it’s time to put it to use during ‘Football School,’ OTAs and minicamp.”

Okoye certainly has the strength and build to prosper in the NFL, at 6-foot-6 and 304 pounds.

Now, Okoye is in the mix to show what he can do with all that knowledge he gained in his season of study. Like Carradine – who also was sidelined by injury his rookie season – Okoye will be getting a late start to contribute.

Unlike Carradine, howeve, Okoye has no track record of success in the game. He remains an unknown quantity. He was credited with one quarterback pressure late in one preseason game, but that’s it. If he doesn’t pan out, it’s no real loss for the 49ers, who already are deep on the line. But if he can outplay some of his teammates, the 49ers may have themselves a gem – even if that appears to be a long shot right now.

Okoye has given much credit to his line coach, Jim Tomsula, for putting in extra time with him, and for his teammates – particularly Justin Smith and McDonald – for helping him adapt and showing him what he needs to do to be a pro.

“It’s pretty special being in that locker room on gameday at Candlestick,” Okoye wrote last year on the team’s website. “It’s great to see the rest of the team – how they prepare – how Justin Smith and Ray McDonald hit a switch. They changed into not quite different people, but they step up their game. You could see the fierceness in their eyes, and it’s great to be a part of that.

“I look forward to developing that side of my game, that tenacity, that aggression, that fierceness. I want people to look into my eyes and see what I saw in Justin and Ray.”